The Tempo/Topaz 2.3 FWD engine shares nothing in common with the 2.3 RWD engine.
The 2.3 rwd block actually debuted in the early 70's as a 2.0 l engine in the Pinto.
I beleive it became a 2.3 around 1974 and the block design stayed relatively the same right up till most recentley in the Ranger.
It has also had a very successfull career in Formula racing .
The motor has lived in the Pinto/Bobcat, Mustang II, just about every Fox bodied car ever (Mustang, Capri,SVO, Fairmount, Zepher,Baby LTD and Marquis,T-bird TurboCoupe, Cougar XR7) ,the Merkur XR4Ti and lastly the Ford Ranger 1983-1997 (some though had the 8 plug head) It even lived shortly in the Areostar from 1986-1988 . The little engine was over-bored in 1998 to 2.5 litres for the Ranger and is still available this way today .